Biomedical subjects

P D Aiello

Publications and source records attributed to P D Aiello.

3 recordsLinked to original sources

PubMed1993

Visual prognosis in giant cell arteritis.

PURPOSE: The visual prognosis in giant cell arteritis (GCA) was evaluated over a 5-year period. METHODS: The authors reviewed the records of all patients with a diagnosis of GCA established at the Mayo Clinic over a 5-year period regarding visual status. Follow-up data for these patients were obtained 5 years later. RESULTS: Of the 245 patients studied, 34 (14%) permanently lost vision because of GCA. In 32 of these patients, the visual deficit developed before glucocorticoid therapy for GCA was begun; in the 2 other patients, the visual loss occurred after the diagnosis was made and therapy was started. Visual loss progressed in three patients after initiation of oral glucocorticoids, and in five other patients vision improved. After 5 years, the probability of loss of vision developing after initiating oral glucocorticoid treatment was determined to be 1% (Kaplan-Meier technique), and the probability of additional loss was 13% in patients with GCA who had a visual deficit at the time therapy was begun. CONCLUSION: The development or progression of visual loss was rare after the initiation of glucocorticoid therapy.

Aged↗

PubMed1988

Extreme warfarin intoxication secondary to possible covert drug ingestion.

A young adult male patient presented with an excessively prolonged prothrombin time (greater than 90 sec) following approximately two weeks of therapy with oral warfarin sodium, in doses between 2.5 and 5 mg/d. Repeated administration of vitamin K and fresh frozen plasma was required to reverse the anticoagulation and maintain a normalized prothrombin time. Serial warfarin plasma concentration measurements were used to interpret the apparently unusual prothrombin time response profile and to detect the possibility of covert drug ingestion.

Adult↗

PubMed1984

Studies on the polyglutamate specificity of thymidylate synthase from fetal pig liver.

Thymidylate synthase has been purified 1700-fold from fetal pig livers by using chromatography on Affigel-Blue, DEAE-52, and hydroxylapatite. Steady-state kinetic measurements indicate that catalysis proceeds via an ordered sequential mechanism. When 5,10-methylenetetrahydro-pteroylmonoglutamate (CH2-H4PteGlu1) is used as the substrate, dUMP is bound prior to CH2-H4PTeGlu1, and 7,8-dihydropteroylmonoglutamate (H2PteGlu1) is released prior to dTMP. Pteroylpolyglutamates (PteGlun) are inhibitors of thymidylate synthase activity and are competitive with respect to CH2-H4PteGlu1 and uncompetitive with respect to dUMP. Inhibition constants (Ki values), which correspond to dissociation constants for the dissociation of PteGlun from the enzyme-dUMP-PteGlun ternary complex, have been determined for PteGlun derivatives with one to seven glutamyl residues: PteGlu1, 10 microM; PteGlu2, 0.3 microM; PteGlu3, 0.2 microM; PteGlu4, 0.06 microM; PteGlu5, 0.10 microM; PteGlu6, 0.12 microM; PteGlu7, 0.15 microM. Thus, thymidylate synthase from fetal pig liver preferentially binds pteroylpolyglutamates with four glutamyl residues, but derivatives with two to seven glutamyl residues all bind at least 30-fold more tightly than the monoglutamate. When CH2-H4PteGlu4 is used as the one carbon donor for thymidylate biosynthesis, the order of substrate binding and product release is reversed, with binding of CH2-H4PteGlu4 preceding that of dUMP and release of dTMP preceding release of H2PteGlu4. Vmax and Km values for dUMP and CH2-H4PteGlun show relatively little change as the polyglutamate chain length of the substrate is varied.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗